National Academies Press: OpenBook

Improving Pedestrian Safety at Unsignalized Crossings (2006)

Chapter: Chapter 8 - Conclusions and Recommendations

« Previous: Chapter 7 - Findings From the Field Study
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Suggested Citation:"Chapter 8 - Conclusions and Recommendations." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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Suggested Citation:"Chapter 8 - Conclusions and Recommendations." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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Suggested Citation:"Chapter 8 - Conclusions and Recommendations." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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Page 61

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59 This study had two main objectives: • Recommend selected engineering treatments to improve safety for pedestrians crossing high-volume, high-speed roadways at unsignalized intersections, in particular those served by public transportation; and • Recommend modifications to the MUTCD pedestrian traffic signal warrant. The first two sections of this chapter provide conclusions and recommendations for these two main objectives. In accomplishing the two main study objectives, the research team also developed useful supporting information on vari- ous aspects of pedestrian safety at unsignalized roadway crossings. This supporting information includes pedestrian characteristics (e.g., walking speed, gap acceptance, and treat- ment activation behavior), motorist yielding, and traffic engi- neering and transit agency perspectives. Conclusions and recommendations based on the supporting information are presented in later sections of this chapter. Guidelines for Pedestrian Crossing Treatments Summary The research team developed guidelines for selecting pedes- trian crossing treatments for unsignalized intersections and midblock locations (Guidelines for Pedestrian Crossing Treat- ments, included in this report as Appendix A).Quantitative pro- cedures in the guidelines use key input variables (such as, pedestrian volume, street crossing width, and traffic volume) to recommend one of four possible crossing treatment categories: • Marked crosswalk; • Enhanced, high-visibility, or “active when present” traffic control device; • Red signal or beacon device; or • Conventional traffic control signal. The guidelines include supporting information for these treatment categories as well as examples and pictures of traf- fic control devices in each treatment category. Several traffic engineers tested the guidelines and provided feedback that has been incorporated into the current version. Additionally, the research team tested the guidelines using actual field data from the field study sites as well as other marked crosswalks without treatments. The results of these tests indicated that the guidelines provide appropriate rec- ommendations of pedestrian treatments that substantially agree with engineering judgment. Recommendation The research team recommends that the Guidelines for Pedes- trian Crossing Treatments (included in this report as Appendix A) be widely distributed. The audience and potential users for these guidelines include state, county, and city traffic engineers, transit agencies, roadway designers, and urban planners, as well as consultants for these groups and agencies. Revisions to the MUTCD Traffic Signal Warrant Summary The research team developed and presented recommenda- tions to revise the MUTCD pedestrian warrant for traffic con- trol signals. The proposed revisions were derived from other vehicle-based traffic signal warrants and supplemented with data gathered during the study. The basis for the proposed pedestrian warrant revisions is that the number of pedestri- ans waiting to cross a street should be no greater than the number of vehicles waiting to cross or enter a street. Once this C H A P T E R 8 Conclusions and Recommendations

basis has been accepted, then the existing vehicle-based war- rants can be used to derive comparable warrants for crossing pedestrians. The net effect of the proposed revisions is as fol- lows: (1) the pedestrian warrant will be slightly easier to meet with lower pedestrian volumes on streets with high vehicle volumes, and (2) the pedestrian warrant will be slightly more difficult to meet on streets with low vehicle volumes. In addition to traffic signal warrant revisions, the research team identified two other MUTCD sections that could be revised. The first revision is a minor addition to an enumer- ated list of alternatives to traffic control signals (MUTCD Section 4B.04). The recommended addition suggests the use of median refuge islands or curb extensions as alternatives to traffic control signals that could improve pedestrian safety. This first revision was accepted by the NCUTCD in January 2006 and could appear in future MUTCD versions (after additional reviews by others). The second recommended revision is the inclusion of a new type of highway traffic sig- nal in the MUTCD called “pedestrian beacon.” This revision was endorsed by the Signal Technical Committee in January 2006 and will go to sponsors during the Spring of 2006. The Signal Technical Committee will respond to sponsors’ com- ments during their Summer 2006 meeting. The pedestrian beacon represents devices that this study found to be most effective on high-volume, high-speed roadways. Recommendation The research team recommends a continuing dialog with the appropriate NCUTCD technical committees in order to encour- age adoption of these recommended revisions to the MUTCD. To change the MUTCD, it may be necessary for such a dialog to continue beyond the duration of this study. Members of the research team have already presented proposed MUTCD revi- sions,with some elements received favorably and other elements requiring considerably more discussion and debate. Walking Speed Summary Pedestrians have a wide range of needs and abilities. The MUTCD includes a walking speed of 4.0 ft/s (1.2 m/s) for cal- culating pedestrian clearance intervals for traffic signals. It also includes a comment that, where pedestrians walk more slowly than normal or pedestrians in wheelchairs routinely use the crosswalk, a walking speed of less than 4.0 ft/s (1.2 m/s) should be considered in determining the pedestrian clearance times. Other research studies have identified pedes- trian walking speeds ranging from 2.2 to 4.3 ft/s (0.6 to 1.3 m/s). In 2002, the U.S. Access Board used the guidelines pre- pared by the Public Rights-of-Way Access Advisory Commit- tee and recommended a universal maximum pedestrian walking speed of 3.0 ft/s (0.9 m/s) (57). One of the pedestrian characteristics collected during the field studies was the time for pedestrians to cross to the mid- dle of the street or median and then to the other side of the street. Using the distances being crossed, the walking speeds of the pedestrians were determined. To permit comparisons with other studies, the data were grouped to reflect the following: • Younger—includes pedestrians between the ages of 13 and 60 and • Older—includes pedestrians older than 60. The following conclusions were developed for walking speed: • The 15th percentile walking speed for younger pedestrians is 3.77 ft/s (1.15 m/s) (sample size of 2,335), and the 15th percentile walking speed for older pedestrians is 3.03 ft/s (0.92 m/s) (sample size of 106). • The older pedestrian groups (male, female, and both) had 15th percentile walking speeds that differed statistically from the 15th percentile walking speeds of the younger pedestrians. • Two studies with databases that contain more than 2,000 pedestrian crossings are the 1996 Knoblauch et al. study (14) (data collected in 1993) and this TCRP/NCHRP study. The data collected in 2003 for the TCRP/NCHRP study identified a slower walking speed for the younger group—(3.77 ft/s [1.15 m/s] as compared with 4.02 ft/s [1.23 m/s])—than found in the 1993 data collected for the Knoblauch et al. study. • When both older pedestrians and younger pedestrians are considered using the Knoblauch et al. data (sample size of 4,459), the 15th percentile value of 3.53 ft/s (1.08 m/s) was determined. Recommendation Comparing the findings from this TCRP/NCHRP study with previous work resulted in the following recommendations: • 3.5 ft/s (1.1 m/s) walking speed for general population and • 3.0 ft/s (0.9 m/s) walking speed for older or less able population. These values are being considered for the upcoming revision to the MUTCD. Motorist Compliance Summary The research team chose motorist compliance (yielding or stopping where required) as the primary measure of effec- tiveness for engineering treatments at unsignalized roadway crossings. Motorist compliance data were collected at 42 60

study sites that included nine different types of pedestrian crossing treatments. In addition to collecting motorist yield- ing behavior for general population pedestrians, the data col- lection personnel also staged street crossings to ensure consistency among all sites as well as adequate sample sizes. The research team analyzed motorist compliance thoroughly and used the findings to support development of the Guide- lines for Pedestrian Crossing Treatments. Conclusions about motorist compliance are as follows: • The crossing treatment affects motorist compliance. Those treatments that show a red indication to the motorist have a statistically significant different compliance rate from devices that do not show a red indication. These red signal or beacon devices had compliance rates greater than 95 percent and included midblock signals, half signals, and HAWK signal beacons. Nearly all the red signal or beacon treatments evaluated were used on busy, high-speed arte- rial streets. Pedestrian crossing flags and in-street crossing signs also were effective in prompting motorist yielding, achieving 65 and 87 percent compliance, respectively. However, most of these crossing treatments were installed on lower-volume, two-lane roadways. • The measured motorist compliance for many crossing treatments varied considerably among sites. For example, treatments in the “active when present” and “enhanced and/or high-visibility” categories have a wide range of compliance rates as shown in Figure 24. In fact, a statistical analysis could find no significant differences between many of the crossing treatments, even though the difference in average compliance rates appeared to be practically signif- icant (30 to 40 percent greater). The research team con- cluded that other factors (such as, roadway width, speed limit, and street environment) affected compliance rates. • The number of lanes being crossed influences the effec- tiveness of the crossing treatment. All but one of the treat- ments on the two-lane roadways performed at a better than 75-percent compliance rate. On four-lane roadways, com- pliance ranged from below 30 percent to 100 percent. • The posted speed limit influences the effectiveness of the crossing treatment. Flags, refuge islands, and high-visibility markings all have higher compliance rates on lower-speed roadways. On a 35-mph (55-km/h) roadway, the best com- pliance rate observed for a treatment not showing a red indication to the motorist was about 58 percent. Compli- ance rates for the devices on 25-mph (40-km/h) streets all were above 60 percent. Compliance rates were as low as 15 percent for streets with a 35-mph (55-km/h) speed limit. Recommendation The research team recommends the addition of red signal or beacon devices to the engineer’s alternative for pedestrian crossings. The study results indicated that all red signal or beacon devices prompted high levels of motorist compliance on high-volume, high-speed streets; however, only a traffic signal is currently recognized in the MUTCD, and the current pedestrian signal warrant is very difficult to meet. Thus, in the current situation, engineers cannot easily use those traffic control devices that appear to be most effective for pedestri- ans on wide, high-speed streets. As indicated previously in the signal warrant recommendations, the research team recom- mends the inclusion of a new type of highway traffic signal (a “pedestrian beacon”) in the MUTCD. These pedestrian bea- cons would have different signal operation modes than tradi- tional traffic control signals and would include the red signal or beacon devices that this study found to be most effective on high-volume, high-speed roadways. 61

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TRB's Transit Cooperative Research Program (TCRP) and National Cooperative Highway Research Program have jointly produced and published Improving Pedestrian Safety at Unsignalized Crossings. The product, which can be referred to as TCRP Report 112 or NCHRP Report 562, examines selected engineering treatments to improve safety for pedestrians crossing high-volume and high-speed roadways at unsignalized locations. The report presents the edited final report and Appendix A. TCRP Web-Only Document 30/NCHRP Web-Only Document 91 (Pedestrian Safety at Unsignalized Crossings: Appendices B to O) contains the remaining appendixes of the contractor's final report.

A summary of TCRP Report 112/NCHRP Report 562 as published in the July-August 2007 issue of the TR News is available online.

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